The present invention generally relates to a motor-and-pump assembly and more particularly relates to a motor that is selectively engaged to two or more pumps.
Motor-and-pump assemblies of this type are used in many applications and are especially fit for employment in automotive vehicles. A motor-and-pump assembly comprised of a pump unit and an electric motor driving the said assembly is disclosed, for example, in DE 43 15 826 A1. The pump unit is configured as a radial piston pump and designed for use in automotive vehicle brake systems to supply brake fluid. Patent application DE 197 07 248.1, which has not yet been published, describes a brake system for automotive vehicles comprising a motor-and-pump assembly which generates by means of a pump a pneumatic pressure below atmospheric pressure for the operation of a brake force booster, on the one hand, and generates by means of another pump a hydraulic pressure for the operation of a slip control device, on the other hand.
In addition to the media referred to hereinabove, there is the demand for the supply of further media in an automotive vehicle. Usually, additional motor-and-pump assemblies are used to supply these media such as fuel and water. Because the economy of weight and space is nowadays a major objective in the automotive vehicle industry, it is disadvantageous to use a large number of motor-and-pump assemblies in an automotive vehicle which cause additional weight and require additional space.
An object of the present invention is to provide a motor-and-pump assembly which is capable of supplying as many media as possible in parallel and which thereby minimizes weight and space requirements.
One essential advantage of the present invention is that at least two pump units are generated by a joint drive motor, whereby weight and space is economized due to the omission of the otherwise required further drive motors.
Principally, each one of the pump units can comprise any possible pump principle. Thus, the pumps may e.g. be configured as piston pumps, vane-type pumps, or gear-type pumps. To enable simultaneous or separate operation of the pump units, a freewheeling device may be arranged in each case between the motor and the pump unit. This renders it possible to operate the pumps individually or jointly depending on the direction of rotation of the motor. Depending on the structural volume requirement of the pump units, they may be arranged within or outside the motor housing. When the pump units are favorably preassembled as subassemblies, the pump units may also be flanged from the outside to the motor housing.